dragonboard: Add helper script to simplify fetching the correct vendor-package am: 681b625a35 am: 9246204517 am: 34458c6656

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/1962360

Change-Id: I63cc69ea54e36c78f46b9efc9c7f40d7d6e0d2ca